1. Field of the Invention
The present invention relates to lighting, and more particularly to lighting that employs a plurality of solid state optical emitters such as light emitting diodes (LEDs).
2. Description of the Related Art
One form of signage commonly employed, both indoors and outdoors, is channel lighting. A canister or can comprising, for example, metal, and shaped in the form of a letter or character houses a source of light such as one or more fluorescent bulbs. The can has one translucent surface that also takes the form of the letter/character. When illuminated, light from the light source is transmitted through the translucent surface, creating a bright region in the shape of the letter or a character. The drawback to conventional channel lighting is that the fluorescent tubes bum out and require replacement; such replacement is inconvenient and costly. To overcome this problem, the fluorescent bulbs are currently being replaced with solid state optical emitters, such as LEDs, which are placed within the can. The LEDs, however, which are effectively point sources, create bright localized regions referred to herein as hot spots that are visible through the translucent surface. Such hot spots are distracting and aesthetically displeasing.
Thus, what is needed is a lighting apparatus for uniformly illuminating the channel light.
In one aspect of the invention, an illumination apparatus comprises a lighting segment which comprises a plurality of lighting sections. Each of the sections comprises a printed circuit board having a solid state optical emitter mounted thereon. The sections are interconnected by printed circuit board connectors, which serially position the printed circuit boards with edges of adjacent printed circuit boards proximate to each other. The connectors are deformable to alter the orientation in response to an applied force. The sections are electrically connected to each other such that the solid state optical emitters are electrically connected in series. The segments have a current regulator, which controls current through the solid state optical emitter.
In another aspect of the invention, an illumination apparatus comprises a lighting segment comprised of a plurality of electrically interconnected sections. Adjacent ones of the sections are flexibly connected to each other by connections, which permit relative movement therebetween. Each of the sections comprises a solid state optical emitter and an optical element. At least one optical element is a first refractive element and at least another optical element is selected from the group consisting of (1) a second refractive element having different refractive characteristics than the first refractive element and (2) an optical diverter having a total internal reflection surface.
Another aspect of the invention comprises a method of illuminating an elongate strip of translucent material. This method includes energizing a plurality of series-connected light-emitting diodes to emit light. Light is passed from the plurality of light-emitting diodes through a plurality of optical elements, respectively. Each of the plurality of optical elements produces an elongated pattern having a substantially uniform intensity across the pattern. The elongated illumination patterns are imbricated to substantially uniformly illuminate the elongate strip of translucent material.
In yet another aspect of the invention, an illumination apparatus includes a segmented support structure comprising of a plurality of sections, which are movably connected to each other. A plurality of point sources are mounted on the plurality of sections, respectively; and a plurality of non-rotationally symmetric lenses are mounted on the plurality of sections, respectively, to receive light from the plurality of point sources, respectively.
Each of the embodiments described above can be employed in connection with channel lighting, bandlights, and/or contour or accent lighting, for example, on buildings and other architectural structures. Bandlights are discussed in U.S. patent application Ser. No. 09/620,051 entitled xe2x80x9cLighting Apparatusxe2x80x9d filed on Jul. 20, 2000, still pending, which is incorporated herein by reference. Applications of the above-described embodiments, however, are not limited to these.